Meta-data is “data pertaining to data”, and is used as data that explains binary data such as image data, audio data, and the like. However, when binary data and corresponding meta-data are present as independent files, the user must manage the binary data and meta-data at the same time upon moving or copying files, resulting in inconvenience.
In general, in order to facilitate management of binary data and meta-data, various methods that describe binary data and meta-data have been proposed. Such conventional techniques can be categorized into methods of defining new binary formats, and methods that manage those data using databases.
As examples of the method of defining a new binary format, Tiff, Exif, Flashpix, and the like are known as new image formats. FIG. 24 shows the concept of a format in which meta-data is embedded in binary data. As binary data, for example, image data is used. As shown in FIG. 24, a field for describing meta-data is normally allocated in the header field of an image, and the user describes meta-data in that field. By describing meta-data in such way, data can be easily searched and classified. Since binary data includes meta-data, they can be managed by a single file, thus allowing relatively easy file management.
A method of managing binary data and meta-data using a database will be explained below. FIG. 25 shows the concept of the method of managing binary data and meta-data using a database. The method of managing binary data and meta-data, which are present as independent files, using a database or the like, as shown in FIG. 25, is also prevalent. In this case, existing binary data can be used by an existing application without any modifications. However, the method of defining a new format that describes meta-data, and the method of managing meta-data using a database suffer their respective problems.
When a new format that describes meta-data is defined, existing binary data must be converted into the new format, and meta-data must be described in that new format. Furthermore, in order to search binary data using the meta-data in the new format, an application compatible to the new format is required. That is, in order to describe and use meta-data, a large number of steps and dedicated environment are required. Also, in order to process binary data in such new format (e.g., to output an image if the binary data is image data), an application compatible to that format is required, and an existing application cannot cope with this situation.
In addition, since the description method of meta-data is uniquely determined in the new format, a new search routine must be created to create an application that uses meta-data in the new format. Furthermore, in order to describe meta-data in a new field, the specifications of the format must be changed.
On the other hand, when binary data and meta-data are simultaneously managed using a database, meta-data can be neither registered nor used if database software is not available. Also, in order to display registered meta-data, dedicated software is required. Furthermore, when binary data is read out from the database, meta-data does not come with it, i.e., binary data without meta-data is formed.
The aforementioned problems are also posed when, for example, image data is included as binary data, and area information that pertains to an image expressed by that image data is included as meta-data.
Area information is data that pertains to a partial image obtained by extracting an area which has a uniform feature from a still image. This area information is used to detect and recognize objects in an image. However, when no area information is appended to still image data, a still image must undergo area segmentation as a pre-process for detection and recognition of objects in an image. Since area segmentation generally requires huge computer resources and long processing time, the efficiency is poor.
For this reason, it is demanded to manage such area information in correspondence with still image data, as described above. However, when still image data and corresponding area information are present as independent files, the user must manage the still image data and area information at the same time upon moving or copying files, resulting in inconvenience.
Conventionally, no attempt to manage still image data and its area information, as described above, has been made. However, the method of managing these two data in association with each other can be generally classified into a method of defining a new image format and a method of managing those data using a database, as has been explained for binary data and meta-data.
As examples of the method of defining a new binary format for still image data, Tiff, Exif, Flashpix, and the like are known as new image formats. FIG. 26 shows the concept of a format in which meta-data is embedded in binary data. That is, FIG. 26 shows the concept of a format in which area information is embedded in still image data. In this manner, when a field for describing area information is allocated in the header field of an image, and area information that pertains to the image is stored in that field, they can be managed as a single file, thus allowing relatively easy file management.
On the other hand, image data and area information are managed using a database as follows. FIG. 27 shows the concept of a method of managing still image data and area information using a database. As shown in FIG. 27, a method of managing still image data and area information which are present as independent files using a database or the like is available. In this case, still image data is not modified at all, and existing still image data can be directly used by an existing application.
However, the method of defining a new format that describes area information, and the method of managing meta-data using a database respectively suffer the same problems as those of management of binary data and meta-data.
That is, when a new format that describes area information is defined, existing still image data must be converted into the new format, and area information must be described in that new format. Furthermore, in order to use area information in the new format, an application compatible to the new format is required. That is, in order to describe and use area information, a large number of steps and dedicated environment are required. Also, in order to process still image data in such new format (e.g., to output an image if it is image data), an application compatible to that format is required, and an existing application cannot cope with such situation.
In addition, since the description method of area information is uniquely determined in the new format, a new read routine of area information must be created to create an application that uses area information in the new format. Furthermore, in order to describe area information in a new field, the specifications of the format must be changed.
On the other hand, when still image data and area information are simultaneously managed using a database, area information can be neither appended nor used if database software is not available. Furthermore, when only still image data is read out from the database, area information does not come with it, i.e., still image data without area information is formed.